Glider torpedo



Jan. 11, 1944. H A GURNEY 2,339,011

GLIDER TORPEDO Filed Aug. 11, 1941 2 Sheets-Sheet l a H/ lwA/v A.GUR/VEY V HA RA /s, mic/7g F05 775/? & HA RAP/5 J 1944- H. A. VGURNEY2,339,011

' GLIDER TORPEDO Filed Aug. 11, 1941 2 Sheets-Sheet 2 Arro IVE K5.

Patented Jan. l1, 1944 UNITED- STATES PATENT OFFICE GLIDER. TORPEDOHarlan A. Gurney, Enclno, Calif. Application August 11, 1941, Serial No.406,247

6 Claims.

My invention relates to aerial warfare, with special reference to aerialbombing and is directed to an improved form of bomb providing forautomatic flight control.

In bombing operations the problem is to launch a bomb from a movingairplane von a path to reach a given objective. Dropping a bomb on acurved trajectory from level flight involves a special technique to takeinto account a number of critical factors and is not suitable for manytypes of targets and operating conditions. For such targets andoperating conditions some type of dive bombing is required. One of thegreat advantages of dive bombing is the simplicity of the aimingtechniquie, since it is necessary merely to dive the airplane toward theobjective to launch the bomb on an eflective path. A seriousdisadvantage of ordinary dive bombing, however, is that the airplanemust swoop relatively close to its target along a path that is highlyvulnerable to anti-aircraft fire.

One object of the present invention is to achieve simplicit of aimingcomparable to that of dive bombing but without undue exposure of theaircraft to defensive batteries at the target. More specifically stated,it is proposed to provide a glider torpedo that may be launched at asubstantial distance from the target from a position unfavorable foranti-aircraft guns at or near the target.

With reference to the design and construction of such a glider torpedo,the invention has the following objects: to provide a glider that willautomatically maintain a given heading after release from the airplane;to provide a gyro glider control that is automatically uncaged foroperation when the glider is released; to utilize the surrounding airstream to energize the gyro means; to utilize the surrounding air streamto actuate the glider control surfaces in response to the gyromechanism; and to provide automatic means to cause the glider toinitially swerve away from the airplane when released for glidingflight.

A further object of the invention is to so design a bomb and so mountthe bomb on an airplane that the bomb will, in efiect, sustain its ownweight in the course of airplane flight to the zone of operations. Byvirtue of such an arrangement the airplane need not be designed to carrya great weight and a light combat plane may be used to carry arelatively heavy bomb. An additional load is, of course, imposed on thepower plant of the airplane in carrying the bomb, but as soon as thebomb is released the airplane recovers its full efllciency and capacityto maneuver for ofiense or defense.

Other objects and advantages of the invention will be apparent from thefollowing detailed description taken with the accompanying drawings.

In the drawings which are to be considered as illustrative only,

Fig. 1 is a side elevation of an airplane equipped with a glider torpedoin accord with my invention;

Fig. 2 is a front elevation of the glider torpedo in gliding flight;

Fig. 3 is a plan view of the glider torpedo;

Fig. 4 is a side elevation of the rear portion of the glider torpedowith a portion of the glider wall removed to show the internal controlmechanism;

Fig. 5 is a perspective view on an enlarged scale of the mechanism inone of the gyro controls;

Fig. 6 is a horizontal section on an enlarged scale through a valveshown in Fig. 5;

Fig. 7 is a vertical section on an enlarged scale through a pneumaticactuator employed in the control arrangement; and

Fig. 8 is a vertical section through an automatic device employed in thearrangement. The torpedo glider shown in Figs. 1 to 3 has a body orfuselage 20 containing a quantity of explosive and housing certaincontrol mechanism, a pair of wings 2|, a fin 22, a rudder 23, ahorizontal stabilizer 25, and an elevator 26. The upper surface of theglider body 20 is provided with three loops or eyes 21 (Fig. 3) that areadapted for releasable engagement by suitable shackles 28 (Fig. 1) onthe under side of the transporting airplane '30. When the glider ismounted as shown in Fig. 1, the glider will be substantiallyself-sustaining in the course of airplane fiight, the wings of theglider being sufficiently spaced from the wings of the airplane to avoidany substantial mutual interference with aerodynamic efficiency.

The control system of the glider torpedo may be disposed in a rearwardcompartment 3| in the manner illustrated in Fig. 4. The principal partsof the depicted control mechanism are: a directional gyro unit generallydesignated 32 operatively connected to a control valve generallydesignated 33 for governing the rudder 23; a pneumatic actuator 35 formoving the rudder 23 in response to operation of'the valve 33; a secondgyro unit generally designated 36 operatively connected to a controlvalve generally designated 31 governing the elevator 26; and a pneumaticactuator 38 for moving the elevator 26 in regimbal ring sponse tooperation of the control valve 81. While I have chosen to energize thecontrol system pneumatically and, as will be explained, have chosen toderive the pneumatic energy from the air stream around the glider, itwill be apparent to those skilled in the art that other energizingarrangements and expedients may be employed within the scope of myinvention.

On the under surface of the torpedo body I mount an air scoop 48 that isthe equivalent or a forwardly directed Pitot tube to create a zone ofrelatively high pressure therein. To create a zone of relatively lowpressure, I may mount a Venturi tube 4| on the exterior of the torpedobody or may rely simply on the well known low pressure effect achievedby placing a port in the torpedo body perpendicularly to the exteriorsurface of the body. The provision of either or the two zones mayprovide a sufllcient pressure differential to operate the controlmechanism, but I prefer to achieve a relatively high pressuredifferential by utilizing both zones.

The direction gyro 32 comprises a housing 42 containing a gyro which maybe of the wellknown construction shown in Fig. 5. In this construction arotor 45 driven by a nozzle 48 is mounted on suitable bearings 41 in ahorizontal gimbal ring 48, the horizontal gimbal ring being mounted inturn by trunnions 58 in a vertical The vertical gimbal ring 5| iscarried by a horizontal rotary table 52 that is suitably mounted on afixed base 53, and the upper side of the vertical gimbal ring is fixedlyconnected by a fitting 55 to a vertical valve stem 58 of the controlvalve 33.

The caging rod 51, which corresponds functionally in major respects tothe usual caging knob of a conventional directional gyro, terminates ina caging tooth 58, the caging tooth being adapted to retractably enter asuitable notch 60 in the rotary table 52 to immobilize the verticalgimbal ring 5| until the time arrives to release the glider and gyrocontrol. Since it is desirable to likewise immobilize the horizontalgimbal ring 48, a caging arm 8| of a well-known construction is includedin my preferred arrangement. When the caging rod 51 is moved inward toseat the caging tooth58 in the notch 88, the caging arm BI is tiltedupward by 'means well known in directional gyros, such means including abracket 82 carried by the caging rod and a concealed springplunger'operated thereby. Upward tilting of the caging arm 5| forcefullybrings a flat surface of the caging arm against a flat surface of thehorizontal gimbal ring to force the gimbal ring into a planesubstantially perpendicular to the plane of the vertical gimbal ring 5|.

To provide a jet of air from the nozzle 48 for propelling the rotor 45,the nozzle may be connected directly to what may be termed a pressureline 85 from the air scoop 48 and the gyro housing 42 may be connectedto what may be termed a vacuum line 86 from the venturi 4|, the gyrohousing being designed for little or no air leakage to make thedescribed arrangement pneumatically effective.

The control valve 33 may, as indicated in Figs. 5 and 6, include acylindrical body 81 with an axially located vacuum port 88 connectedwith the vacuum line 88, a peripheral pressure port 18 connected to thepressure line 85, and two spaced peripheral control ports 1| and 12.Within the valve body 81 is mounted a rotary valve member 13 unitarywith the previously mentioned valve stem 58. The rotary valve member 13is peripherally recessed to cooperate with the surrounding valve body 81in Iorming two pressure spaces 15 and 16 and an intermediate vacuumspace 11. The two pressure spaces 15 and 18 are continuously incommunication with the pressure port 18 by virtue 01 two bores 18 in therotary valve body 13, and the vacuum space'11 is continuously incommunication with the vacuum port 88 by virtue of a radial bore." andan axial bore 8| in the rotary valve member.

The described valve construction is such that when the valve is in theneutral position indicated in Fig. 6, a portion 82 0! the rotary valvemember 13 between the pressure space 15 and the vacuum space 11 cuts oilthe control port 1| and simultaneously a portion 83 o! the valve memberbetween the pressure space 15 and the vacuum 7 with the control port 12.

space 11 cuts 011 the control port 12. It the valve member 13 is rotatedirom its neutral position in a clockwise direction, as viewed in Fig. 6,the pressure space 15 is shifted into communication with the controlport 1| and simultaneously the vacuum space 11 is placed incommunication Counterclockwise movement will produce the opposite effectof placing the pressure space 18 in communication with-the control port12 and placing the vacuum space 11 in communication with the controlport 1|.

The control port 1| of the control valve 33 is connected by a pipe 85 toone side of the pneu- 'matic actuator 35 and the control port 12 isconnected by a pipe 86 to the other side of the actuator. As shown inFig. 7, the pneumatic actuator 35 is in the form of a chamber that isdivided by a diaphragm 81 into two compartments 88 and 98, each of thecompartments being provided with a small bleeder port or vent 9| to theatmosphere. The diaphragm 81 is connected to an operating rod 92 that inturn is operatively connected to an arm 93 unitary with the rudder 23.It is apparent that relative rotation of the valve member 13 fromneutral by the gyro will cause low pressure in one of the compartments88 and 88 and high pressure in the other compartment with consequentactuation of the rudder, the direction of rudder movement depending onthe direction of relative rotation of the valve member.

The arrangement for controlling the elevator- 28 is similar to' theabove described arrangement for controlling the rudder except that thecontrol valve 31 associated with the gyro unit 35 is disposed on asubstantially horizontal axis. The gyro unit 38 includes a housing intowhich extends a longitudinally movable caging rod 98. Concealed withinthe housing is a gyro rotor (not shown) having a sub-.

stantially vertical axis for rotation, the rotor being mounted in avertical gimbal ring (not shown) that is in turn mounted in a horizontalgimbal ring (not shown) and the horizontal gimbal ring being operativelyconnected to the control valve 31. A pressure line 91 from the air scoop40 is connected both to the gyro housing 95 and to the pressure port ofthe valve 31, and a vacuum line 98 from the Venturi tube 4| is connectedboth to the gyro housing 98 and to the vacuum port of the control valve81. One of the control ports of the control valve 81 is connected by apipe I08 to one side of the pneumatic actuator 38 and the other controlport is connected by a second pipe IM to the other side of the pneumaticactuator. The pneumatic actuator 38 controls an operating rod I02 thatis connected to a control arm I03 unitary on the elevator 26.

The four pipes 85, 86, I and |0I associated with the two pneumaticactuators 35 and 38 are equipped with regulating valves I that areadjusted to regulate the rate at which the two actuators respond to thetwo control valves. Adjustment of the regulating valves I05 must bebased upon whatever pressure differential in the pneumatic system isanticipated at the velocity with which the released torpedo glidestoward its objective.

It is contemplated that the gyro units 32 and 36 will be uncagedautomatically upon release of the torpedo glider from the airplane, andit is further contemplated in the preferred practice of my inventionthat the released glider will initially swerve downward clear of theairplane. The means for automatically uncaging the two gyro units may beseparate and apart from the means for causing the initial swerve of thetorpedo glider, but in the present arrangement these two means arestructurally combined.

In the combined structure I employ a valve body I06 (Fig. 8) having twoports I01, one of the ports being connected to the previously mentionedvacuum line 66 and the other port being connected by a pipe I08 to thepreviously mentioned pipe I00 leading to the actuator 38. In effect thearrangement provides a by-pass from the vacuum side of the pneumaticsystem to the actuator 38 around the control valve 31. Inside the valvebody I06 is a valve member I 09 that may be moved from the open positionshown in Fig. 8 to a position cutting ofi flow between the two portsI01. The'valve member I09 is mounted on a control plunger H0 and iscontinuously urged" toward its closed position by a suitable springl II. The upper'end of the control plunger IIO isformed with a suitablehead II2 that is slightly'recessed' to receive the lower end of a fixed.finger II3 that extends downwardly from the airplane 30, thearrangement being such that the finger necessarily denresses the controlplunger IIO against opposi- ':ion of the spring III when the glidertorpedo mounted on the airplane by the shackles 28. Release of thetorpedo glider by the shackles permits the spring III to move thecontrol plunger IIO upward to a position at which the valve member I09cuts off flow through the valve body I06.

Preferaby some provision is made for delayed action in the upward returnof the plunger I I0 at a time interval of delay unafiected by changes inatmospheric pressure. In the present structure, the valve member I09 isin the form of a piston and a suitable liquid is introduced below thepiston for a dash-pot action. The liquid is supplied from a reservoirII4 through a pipe H5 and passes through a metering orifice II6controlled by a manually adjustable regulating valve III.

The lower end oithe control plunger IIO extending downwardly from thevalve body is connected to a pair of links II 8 that are connectedrespectively to a bell-crank II9 on the gyro unit 32 and a bell-crankI20 on the gyro unit 36. The bell-crank H9 is operatively connected tothe caging rod 51 of the gyro unit 32 and the bell-crank I20 is likewiseconnected to the car;- ing rod 96 of the second gyro unit 36.

Preparatory to mounting the torpedo glider on the under side of anairplane the rotary tables of the two gyro units are disposed in rotarypositions to receive the caging teeth on the inner ends of the twocaging rods. When the glider is connected to the shackles 28 of theairplane, the control plunger I I0 is automatically depressed byengagement with the airplane finger I I3 with the result that the twogyro units are caged or immobilized, and the valve member I09 is shiftedto open position. It will'be understood that when the two gyro units arecaged, the corresponding control valves 33 and 31 are in neutralposition.

As soon as the airplane takes off with the underslung torpedo glider,the air stream surrounding the glider becomes efiective to create apressure difierential in the control system, with resultant initiationof the air jet flow to energize the rotors of the two gyro units. Sincethe caging of the gyro jets immobilizes the two valves 33 and 31 intheir neutral positions, the pressure difierential does not afiect thetwo actuators 35 and 38 through the valves. It will be noted in Fig. 4,however, that the vacuum line 66 is in communication through the valvebody I06 with the actuator 38 while the airplane is in flight, theresult being the creation of a vacuum in one compartment of the actuator38 to pull the elevator rod forward and thereby depress the elevator 26.

When the pilot of the airplane approaches a target the gyros are cagedbut the rotors of the gyros are adequately energized for control. Thepilot maneuvers the airplane to make good a track toward the target, andwhen he is satisfied with his flying alignment he operates a suitablecontrol to cause the shackles 28 to release the glider torpedo. As soonas the glider torpedo is released, the spring III moves the controlplunger IIO upward to uncage the two gyro units 32 and 36 for control ofthe rudder and elevator. At the moment of release from the airplane theelevator of the glider is depressed, as above described, and thereforecauses the glider to swerve away from the airplane independently of thegyro control in the glider. Since the valve member in the valve body I06immediately cuts oil" the by-pass communication to the actuator 38through the pipe I08, control of the elevator is immediately turned overto the gyro unit 32. In practice the adjustment is such that the glidertorpedo swerves sufliciently to clear the airplane but does not swerveto such an extent as to throw the glider torpedo oil" the intended trackto any significant extent. The launched glider torpedo is automaticallyheld on the intended track by the automatic gyro control notwithstandinginterference by nearby shellbursts. The concussion of exploding shellsmay momentarily shift or divert the glider torpedo, but the gyro controlwill steadfastly operate to align the torpedo glider for movement alongthe track.

Fortuitously a glider designed to sustain substantially the whole of itsown weight while being carried by an airplane in the manner describedwill have a relatively low minimum gliding angle and may be released todescend at a relatively low vertical velocity. One of the importantadvantages of providing for a relatively low rate of vertical drop isthat an altimeter may be employed to control the detonation of theglider explosive in response to change in elevation or atmosphericpressure.- An altimeter cannot be-employed for detonation control on afree falling bomb because of lag in the responsiveness of the altimeterto changes in atmospheric pressures. Thus, the lag in response of analtimeter dropping at 2000 feet per minute is on the order of 150 feet.The rate of drop provided by the described glider torpedo iscommensurate with the rate of response of an altimeter with resultantelimination of altimeter lag and the altimeter may be relied upon todetonate the explosive at a predetermined elevation with reasonableaccuracy.

The preferred form of my invention described herein in detail for thepurpose of disclosure and to illustrate the underlying principles willsuggest various changes and substitutions within the scope of myconcept. I reserve the right to all such departures from the preferredform of my invention that are defined by my appended claims.

I claim as my invention:

1. The combination with an airplane of: a glider carrying an explosiveand adapted for releasable attachment to the airplane, said gliderhaving flight controls including a movable airfoil; automatic means onthe glider to guide the released glider for control of said airfoil to acou'rse determined by the heading of the airplane at the moment ofrelease; means, operative during attachment of said glider to saidairplane, removing control of said airfoil from said automatic means andadapted to swing said airfoil to a position to cause the glider toswerve away from the airplane when the glider is released; and delayedaction means on the glider to restore said airfoil to control by saidautomatic means.

2. An aerial torpedo to be carried and released by an airplane,comprising: a glider carrying an explosive and having movable flightcontrols; fluid-pressure-actuated means on the glider for actuatingaidcontrols; a first valve means to control said fluid-pressure-actuatedmeans; gy-

roscopic means operatively connected with said valve means; a secondvalve means to control said fluid-pressure-actuated means, said secondvalve being movable between an effective position to cause the glider tonose off its course and an ineffective position to place the gliderunder sole control of the gyroscopic means and said firstvalve means,said second valve being adapted to maintain its effective position inresponse to attachment of the glider to said airplane; and yieldingmeans to urge said second valve to its ineffective position upon releaseof the glider- 3. The combination with a main and auxiliary aircraftwherein the auxiliary aircraft is carried by the main aircraft andreleased therefrom, and

said auxiliary aircraft is Provided with its own sustaining and controlsurfaces, including an elevator, of a control apparatus for saidelevator,

comprising: pneumatic means deriving its pressure from the air streamsurrounding the auxiliary aircraft for actuating said elevator; agyroscope; valve means controlled by said gyroscope for regulating saidpneumatic means; a bypass valve member for said pneumatic means having aholding. position for causing said pneumatic means to hold said elevatorin a predetermined position irrespective of said gyroscopecontrolledvalve, and a non-holding position wherein said pneumatic means issubject to regulation by said gyroscope-controlled valve; and meansoperable in the course of releasing said auxiliary aircraft from saidmain aircraft for causing said by-pass valve to move from its holding toits non-holding position.

4. The combination with a main and auxiliary aircraft wherein theauxiliary aircraft i carried by the main aircraft and releasedtherefrom, and which is provided with its own sustaining and controlsurfaces, including an elevator, of a control apparatus for saidelevator, comprising: a pneumatic means for controlling said elevator,including a source of fluid pressure, a pressure responsive elementconnected with said elevator, a control valve for regulating saidpressure responsive element, and a by-pass valve having a holdingposition causing said pressure responsive element to hold said elevatorin a predetermined position irrespective of said control valve, and anon-holding position wherein said pressure responsive element isregulated by said control valve, a gyroscope unit for actuating saidcontrol valve; means for restraining operation of said gyroscope unitand restraining said by-pass valve in its holding position, saidrestraining means being operatively connected with said main air- 1craft to release said gyroscope and move said bypass valve to itsnon-holding position when said auxiliary aircraft is released from themain aircraft.

5. A construction, as set forth in claim 3 wherein a time-delay means isincorporated in said. by-pass valve for delaying movement thereof fromits holding to its non-holding position until the auxiliary aircraft isclear of the main aircraft.

6. A construction, as set forth in claim 4 wherein a time-delay means isincorporated with said by-pass valve to delay movement thereof from itsholding to its non-holding position until the auxiliary aircraft hasmoved clear of said main aircraft.

HARLAN A. GURNEY.

